SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '785c430a00d8eb2c5a4e76ba1acc93aad5ecc135e5ffc1bf6046c1a5d4eae7d0' 
  AND token = 'jIOhn4/OhjgFy8y/LkSUribOBjquFTzskY9FSOJDaDo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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