SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '311a5fe84769fefd267a4ac20374437a650d86a3474efa882e75d89a28fdc647' 
  AND token = 'wiLgwFGJ7qV7JYQcwnV8AIC9abRgFbYUjRZkpw/nfEM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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