SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd94327275f8468913638c026fb4a2e6a236613d7485d97983aa1b15bb77298e8' 
  AND token = 'LH3YS2YI73DcbJTcjamGFX4VZAJbmiS72KFe6ZyxPhw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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