SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '798a65032d2246d749f4ac69eb6725db4ad31bfc12004ed9d0a49ffcaf39829b' 
  AND token = '8roPXcABZkgXbN4wQskqBzZaJL3k7OY5ZhrMDFndMNo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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