SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fff9050d4b3d3cb2359f962d0130da83b95315358f21fdac043dfcf7b0f848ac' 
  AND token = 'BEVzCEmQZOC9HCtLe/rYOuK2H0MgKjvUH2Rzk5/ucyA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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