SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '515d7125d679b6ad3d594da008bde2301acfe332b5d251449bcc0c5cf6903f69' 
  AND token = 'Fq5KRScyp6FbGBc9pJFvhK+DpzTSOWH/mUBDG3TGgwY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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