SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f514b34e24cbdc6927f73b0f3842a6d8660157ab64482f10c13fe505ba925392' 
  AND token = 'F++ldwn1b8MuvHjQqBxQG5H4k2NpJPyKKz8Hy4XmIIg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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