SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7baeab8dd1bb1a043daaff90d4b5b3935c1f38de616685c5b00c850d78dfa928' 
  AND token = 'RNu1g71EaYpjh/BaynLz+1diuXqJCGKDrbX/8MwF7js=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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