SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '04612bd84fb2f30642d6a1e23c7775a76a793fef2ea8aa5c1248f381b30d2179' 
  AND token = 'L0pgznBu4bQGAuhWBZQpucsTW4/sEO48E/Kx8bcqJGs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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