SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4f43b6bfdea6eb2045ee4343b3bfaab0581a834a077437c53a80393490db40f0' 
  AND token = 'pIpRB2iX2Q2vDSHu0kBhFhiA5dBUAmVTBmlOGNr3AtY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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