SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f695d6037d7f358b229d598b79b194984f2b6a33f72dcfaff9498dd67db59bf3' 
  AND token = '57umeCzcJKegBndeXJP79EGILtafmotyK59bkDTiuNY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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