SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f2421e50faac80f78ba59ac664ca1dfcb57e50a1ee87ea124fc13273b0b771ad' 
  AND token = 'Dr52k82BS3rp1tCnZANp6FnTeRrcJybssfuYcLfAWYU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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