SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e0cf5fed783bb9020ae1e67b769123cc19369229ba52ec15db14b1abb24752e3' 
  AND token = 'PfoOeJEfFS5v/QpmkVeT0SAeyojzGF7k35bh8XI7Iiw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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