SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5750b46c124fd9c260efd4bc0087bc224773d3bc361304269bafde4b24c1b28e' 
  AND token = 'LxKiOKk0bdJj6lx81nzXa+Rr+mLPo7uyktD8zmVE1DU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00072

JSON explain

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