SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c692d58c2dfa32ce1bece7160e216fe11012cc448e200e6c41b8032463cadf29' 
  AND token = '9pz0pZfgIhOJEcNBUrnPy/yd+jyXOybSLLSS/m2U4/I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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