SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '836294dbbd855c6309b60e6bcec3090d6e44e6522c9fc9f29f459871bdf1f9ff' 
  AND token = 'YF8rsfGQI+TlarRLJOlhp3/Cz0g5EJu/m1dXV4g8Yic=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}