SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '665083b57d249c6d16e87ff342dade37d701205b2fcd912638d563dbcc39b946' 
  AND token = 'ZTAIBgvAEpEVFQM7g/SxCMs7bR33PQXuS2rBlkQdgAQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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