SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '85f46735acd3d49b95c16e410e2622eae215c7ba67c0ea1affd2f16312edf9a5' 
  AND token = '0dF4RDOxlvI3bhLopfZetRzZcOsz5ONFP+i0haX7g3o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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