SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a7586dd9849c3369f3ae11bb6e717857aab42b82c270fbbd0c013e475eaf9abe' 
  AND token = 'sNrG7GUNv7jEEc/29iBZe6xQdV6PuLYzVFCJNMvXQGo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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