SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '65fbe8a9e88945ac90bad9442ef593d4582a1744c1c23899cafda56f8c0e8ce2' 
  AND token = 'WHdh6gAWYXAdUkQJGSEgyvBIxCcZfg7hLQXW/+Ywx4A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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