SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6398046a3da9775c9afb1aeac569b1c87859d8048650ed223a2f10aac5be5ddb' 
  AND token = 'iFT83PyDDZgeZa6rSauYe1XpdpmtFAzUsgTPvroQ0SY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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