SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '52cd35c926dd63d0e48f41581cbb11fbbdd9685a0b76fd22b717b07b7dfaadb0' 
  AND token = 'Cluq84vCEnth53XZdYsrTuMFX9rTlRhG6+kVdiJfPwI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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