SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a5b878dc6ed67b12216fffe30bbeb76b58ce39835e2770151c91522e64142c48' 
  AND token = 'oYfk7VsvSKMk3Ujn7eeppwiXhmQeJ/N5TnAFgnTZSGE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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