SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd20580ad565e1acec2ed3897bb89ad153981167d3134eff15bc8e0ce493f2720' 
  AND token = '/eSBxjm+Gw46b2zCUkln2QaFvQszhkaSbZfBMD90v+I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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