SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6e5fec69dd8cc89958bb57dc5c018f3cba9db95dd9566de0160c3204558f38c6' 
  AND token = 'bGltLsjqarlopMfAiFdYDMMZpTBStCSqIzueNly7ft4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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