SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b7bc9cd730498d0b7342f42964ba7e6ad592ea829d2dce831a2b434dea57fe5b' 
  AND token = 'g0uWmBWRIfeJnDqhS228iCKoeVG6qNOZ51Irm66LQCA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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