SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '97c68333f5dc01a24663f0af0c0c260389ca9beb0db425310bb9e09654a7623e' 
  AND token = 'lS4fi8TJag1zdF29gg6Xb4/JhosOlOhrXCmor2Kw/u0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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