SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8cc90bbcb2cc234247272e1d453aec640ded8ff6102e0306d50c089e9cc66e70' 
  AND token = 'dXAnPN7ifqNA2cowd3ogkSvsbljaZ5InIvI6XKml2j0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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