SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '2a0e0a081962dc37384dea166301119c744bd03a9658fc94184d896683f28a89' 
  AND token = '5BAndQdw0Vm4Uv0Zcim9TI5V2i80+Qrf6Dd7QhW5vHQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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