SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7e5e148c1d3d8a7cc1fd13d50942fc02d17e5c170ddec3ac80c3ae0f9daff535' 
  AND token = 'DZWRdVxxqTztkaCh0Y7iCRhLkHoWfhxmVyyPK3fcKCQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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