SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f1362751f94f5059e487e69f0b4516d21be72bf4e195140ed088170ddb9273a5' 
  AND token = '96l+UwWizOMNc3Tj6i/Vy2Sv424hUflsNEKR2Rr+WbM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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