SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '070c15b0a00b45b9cfded143bc5361266676c1999835eed9d69c49ea96845cf7' 
  AND token = 'efLHGHoprGqDyUmWwYZVcd6FEmHxZ8XyXuknmenA4wg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}