SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '297c65322b2ab277870b5fc17fd83097efbdc8ee3fefbdea039c2c904328d46d' 
  AND token = 'uPah8ZjIR2zMiPk+kuVBjuObGuYliI1fmItxqWTGyEI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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