SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '10c92cb01e2f56de282e1a7bd1affddd3f4e854e31b96b9971754e1b6f395628' 
  AND token = 'Jl/+KS7MxkUyMMMvXKx+91PDDSSrFYh73d2f7mvya8o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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