SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ca37555293aac5dc57156941ae8a1cb9573af9343c343cbcd5e209f03781f044' 
  AND token = 'Ba0Trqju1ulDabgXgSpb9kdrHba2B39rbvIR1rk5TMQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00082

JSON explain

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