SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4f8bab89946610c01fcb6b6cb48680f02e182f8da87619c75120ba468466ee88' 
  AND token = 'MNattzHX9JiHYAXc+S0kRLuVM1Ov/eKNSS/yC0HmrQw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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