SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8468faf7d9300512a94226014e4ad69f0de5d32fb9356ace2d20a254326d0deb' 
  AND token = 'Ve6CySvdi3R5cxT3n9frEt4ztlcqPKxSBGz4J2PbRCY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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