SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2c0f69fcbd53d104146f94348268114e87d3a1a6fb696db80fee36c2239568fd' 
  AND token = '/q2PW0zJdgOa/lSZZjKd8VZ5Zku1nskFWsEf+zSwcsw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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