SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '707152678ddc2533d76a9a041c7c7fc8533f0ceb26da35689866eb29f28f4d02' 
  AND token = 'pF8m3hQKfvMihpxQHzF4Yft4skQCgXDpAQRJg6ghcbQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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