SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a177166214f5c22bd46561cc5cb1092d37208caf24e5611eeb0d9d6ca85b33db' 
  AND token = 'FL05YsPzEPDq/vXZiqDoMznRy4skx0aCV67wbzaGhxY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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