SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a5ed7103c09f9ead3f441e970601a9bdd7eb772fd562172756f38574a9ebf88b' 
  AND token = '8o50Uht12pVfgpzF/uGBoxsYMRg6v7ayqvjDUD0E2Y4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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