SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b0d0bd00115670b996858a624334c60b043d2c8a2a034564205168bf39f17d3c' 
  AND token = 'SVFjBpQWZvU7ShJv0IMSGgT7K30RRjXNjlSBEjs+Kfo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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