SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aeffe5547d4c6bafc17112c3e592f77b180d4d84c0cba1bfba6ad2e10d9b3fbf' 
  AND token = 'a8CoUIiIQ8fHRZwGARfwULNKweCPDtGCLRzdVHwdQvQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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