SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5154b036f7f8bb6c7d14767c8553b61bc01b5954b1b2f8824638879e0ecbbef9' 
  AND token = 'S+sGriFQdswBBtSxc3UbgAcvnLRYZkqjiauYIqkG0KE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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