SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '417e72de7842f46f02dda8d3ac0973b5e1a127646d9610f08bc222385a5c90f9' 
  AND token = 'lfa5KoLoh3XnpfsDUI7lzKkqxjHZCabCtB10n4vattg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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