SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '37e8aab7d09e5bc69ba22c281172380db81eac41bf8af8a4343659e10f40ea24' 
  AND token = 'FoYfTD/Nzs+PdgEQqzE07JZ2GsGkTcmuEx6ND3QAIAA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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