SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '53c953de2d5244ac1311159253bca81117f8bba2e78184a0a96c0a1af82dc9f8' 
  AND token = 'D2CJddsep41txhWdo6oBadheayB79U/615UBNktHM/0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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