SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '71854160527407d89adc5a95bf2aabdf55dbda9606101a935e38463a508e21f6' 
  AND token = 'hO3G8nCK6bD4uWQhuKWs4FFasJnAgxLkntvwYwXPR6U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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