SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1e36e04b0077a57811300785f8d859f6cacb1a47f2490ad7efec2aa708a40860' 
  AND token = 'A4yGGYUICa/s3vZCGARAQAzVzUKIR1yJBihn/jj9sRI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}