SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5fddbf4546cd50ed590b3ad208cf2f9eaa90772d037fda45e6c1d63416124743' 
  AND token = 'DzgD6AMvbjq3yon7VfoAEDlTFin3UoJaAKPXlw8qJoo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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