SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f5bc4d84106b1b2dc32addc633c18caf9bd9b79d3bc4e451f2ecb95df185451b' 
  AND token = 'pI0qqMnYdRhVsdhgKLcDHslUTpGAMTwXBcvNYChCKoA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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