SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '806b072afadd278fcbd01ae36b12658b0558106bd294ca78eb0226e6ad0ac985' 
  AND token = '2IvGip9/kGYZaoeRbOd4MzxeNOmyvsdHpbAyCR6CExU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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