SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fe8dbaea2017db9ea5cdf8c690a2da366acc4360e701508bdf0155cbb5117382' 
  AND token = '8Q8Lx/bHmQAiWb+N9cd46eJmXziq+koGJtTyX0C9P1M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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