SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '029fbefc13fa070d6fbcfd25d0ebd14a327617f08d0abaa8963f9e4acabeebb1' 
  AND token = 'PL2Lfe2PBu5PQlUIJ8J7upsL+qtF1cpX9oyth8PFPe8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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