SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '323e464926c95092c01215dde256eb64cd75c768fa33fc79852a039ac48bb0a8' 
  AND token = 'jxHLvS4LNgi1SBLfblMn2rU3PYMy4VivPW3rXx/qw+w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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