SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '24fd4a2525b6f1013793f8a9e98b350d08dcccea251f9f00ff035d3c85a3e744' 
  AND token = 'ym84rKOwGqzWU/ygkGPfRSfZtUo6Lhpw/3HFtTGYZkI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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