SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fdca14993b0eaf7f0f240a796c98525bf8fccd6f98457a02d98f9de1a7a937ee' 
  AND token = 'IlSvg0kqRYBGd+gSHE6hbpUX1/Nb2ss0NTFrvzRu3Lg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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