SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f3c01fe1b6af890fc3e18cecd2ee20fa3532d852955ff169a8ed1a652235b70f' 
  AND token = 'f2uN7MtyosmfxDhF40GUOdOmKlvIigO9Z/Ah8mD74yU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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