SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '569955410fde25efbd9bcf2b67e569dc04187c89f1cbd4b770a92a8f7ac15486' 
  AND token = 'v/WBAk5FRz6hZhCnuSf+eWYElX4lL4z3PsS7KM92j8c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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