SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '03b8f2225bd67bd3415a88f186e55c10f239d96a48ea763eda01755ec74d6f5a' 
  AND token = 'hBxSUx7+uRNH2iHK9ccNA48K1intsns0iYSczR8Y3T8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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